While it’s totally up to you to decide which type of underwear you prefer, there’s no denying that wearing a thong every day can impact your health. If you’ve been dealing with yeast infections, odors, and/or itchiness, it may be that skinny piece of fabric that’s to blame.

That’s not to say, however, that thongs give everyone a problem. If you like to wear them and haven’t noticed any issues, then keep doing your thing. “If a thong is comfortable and not irritating to your vulval area … it is fine to wear one every day,” Dr. Vanessa MacKay, Vagisil Partner and OB/GYN, tells Bustle. But do consider choosing one that’s healthiest for your bits.

“Using a breathable cotton brand will reduce the risk of irritation,” MacKay adds. “If your vulva is sensitive to the thong style, you may increase the risk of irritation and inflammation of the vulva by wearing it daily. I’d recommend wearing what is comfortable for your body.” And always remember to change your underwear after working out so excess sweat and moisture won’t lead to any issues.

That said, don’t put it past thongs to create some vaginal health issues. Read on for a few ways this style of underwear can cause issues, as well as all the (rather surprising) reasons why.

1. Thongs Can Change The pH Of Your Vagina
Depending on the fabric of your thong, you might notice an increase in annoying issues down below. “Any non-breathable fabric can cause excess moisture,” MacKay says. “This can lead to a change in the pH of the vulva and vagina causing a potential overgrowth of bacteria and/or yeast. This in turn can lead to vulval irritation and inflammation.” And that’s not good.

2. They Can Change Odors

All that excess moisture can lead to an increased chance of vulval and vaginal odor, MacKay tells me. If you’ve noticed smells that are out of the ordinary for you, it may be due to a yeast infection or other type of bacterial overgrowth. When that’s the case, it’s definitely time to see your gynecologist. And, it may even mean you need to switch things up when it comes to your fav underwear.
3. And Lead To Itchiness

Again, the very nature of thongs can lead to itchiness and irritation — as well as whatever irritants may be on them. “Harsh fabrics with potential chemical irritants can … lead to vaginal itching,” MacKay says. “This can … include washing your underwear with harsh soaps, laundry detergent, and/or fabric softener.” If you feel itchy, try switching detergents. Or, you might want to consider wearing a pair of underwear that’s a little less intrusive.
4. Thongs Can Shift Bacteria Around

If you think about it, thongs are kind of like floss. They’re thin and stringy and get up between your bits, and as a result bacteria can shift around. “When wearing a thong, there’s a higher chance of bacteria sticking to the thong and taking a ride from the back to the front of your underwear along the fabric, especially if your thong is ill-fitting,” says Katie Fritts, founder and CEO of the underwear subscription service Underclub. If you’re going to wear one, make sure it’s the correct size so that isn’t as likely to happen.
5. The String Can Cause Inflammation

Since thongs get all up in your business, it is possible to experience some chaffing and inflammation due to the string. And, if you’re having issues going to the bathroom (and are wiping more often), Fritts tells me a thong can make matters worse. “The last thing you want is anything else irritating this area,” she says.
6. Wearing One Might Lead To “Thong Burn”
Simply walking around in a thong can cause “thong burn,” or a feeling of irritation from the fabric rubbing against your skin. But if you’re an athlete, or someone who hits the gym on the regular, this issue can be even worse. As Fritts says, “Thongs can cause rashes with athletes who do a lot of floor training exercises that create friction between your butt and underwear (sit ups or any exercise when you are on your back and butt).” Ouch.

7. The Fabrics Aren’t Always Breathable

If your thongs are made of synthetic fibers, then your skin can’t breathe. And when your skin can’t breathe, bacteria are more likely to grow. So, again, look for those cotton versions instead. “Pick something breathable (limits bacterial growth), comfortable, and most importantly, something that makes you feel your best,” Fritts says.
Because, again, whether or not you wear a thong is up to you. But knowing how that little piece of fabric might be affecting your health? That’s always a good idea.